This section provides background information related to the present disclosure which is not necessarily prior art.
Internal combustion engines include one or more camshafts for actuation of intake and exhaust valves. Cam phasers may be coupled to the camshafts to adjust valve timing. Cam phasers provide for relative rotation of a camshaft relative to a camshaft drive during operation to vary valve timing. Relative rotation of the camshaft may be attained by applying a hydraulic fluid to chambers defined in the cams phaser. However, the cam phasers may not be able to be maintained in a desired position when the pressure of the hydraulic fluid within the chambers is below a required level.